Oenothera nutans |
Oenothera nealleyi |
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nodding evening-primrose |
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Habit | Herbs biennial, often appearing glabrous to naked eye, usually strigillose and sparsely to moderately villous proximal to inflorescence, hairs translucent and with or without pustules, pustules not red (in fresh material), inflorescence glabrous, glandular puberulent, or strigillose and glandular puberulent. | Herbs annual, sparsely villous proximally, leaves glabrate to sparsely villous along veins and on margins, usually glandular puberulent in distal parts; from stout taproot. |
Stems | erect, red on proximal parts, green on distal ones, rarely red throughout, unbranched or with branches obliquely arising from rosette and secondary branches arising from main stem, 30–200 cm. |
usually well-branched, 20–70(–100) cm. |
Leaves | in a basal rosette and cauline, basal 10–32 × 3–7 cm, cauline 6–20 × 2–8 cm; blade green to pale green, narrowly oblanceolate to narrowly obovate, or narrowly elliptic, sometimes lanceolate distally, margins usually flat, rarely undulate, bluntly dentate, teeth widely spaced, sometimes sinuate-dentate proximally; bracts caducous. |
in a basal rosette and cauline, basal 3.5–9 × 0.5–1.5 cm, blade lyrate; cauline 1.5–7 × 0.1–0.6 cm, blade narrowly lanceolate to linear, margins sinuate-dentate, undulate. |
Inflorescences | erect, unbranched or with secondary branches just proximal to main one. |
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Flowers | opening near sunset; buds erect, 4–6 mm diam., with free tips terminal, erect, 1.5–6 mm; floral tube 30–43 mm; sepals yellowish green or flushed with red, 10–23 mm; petals yellow to pale yellow, fading pale yellowish white, very broadly obcordate, 14–25(–30) mm; filaments 10–25 mm, anthers 4–10 mm, pollen ca. 50% fertile; style 35–63 mm, stigma surrounded by anthers at anthesis. |
4-merous, zygomorphic, opening at sunset; floral tube 10–20 mm; sepals 11–21 mm; petals white, fading pink to red, elliptic to elliptic-obovate, 10–15 mm; filaments 8–13 mm, anthers 2–6 mm, pollen 90–100% fertile; style 22–36 mm, stigma exserted beyond anthers at anthesis. |
Capsules | erect or slightly spreading, dull green when dry, narrowly lanceoloid to narrowly ovoid, 12–36 × 3–6 mm, free tips of valves 1–1.5 mm. |
ellipsoid or ovoid, narrowly 4-winged, furrowed between angles, 4.5–8 × 2–5 mm, stipe 0.2–2.2 mm; sessile. |
Seeds | 1–1.9 × 0.6–0.9 mm. |
3 or 4 (or 5), yellowish to light brown, 2–3(–4) × 1 mm. |
2n | = 14. |
= 14. |
Oenothera nutans |
Oenothera nealleyi |
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Phenology | Flowering Jun–Aug(–Sep). | Flowering Apr–Oct. |
Habitat | Open, often disturbed sites, stream beds, flood plains, slopes, margins of mixed deciduous forests, roadsides, old fields. | Washes, sandy places, grasslands, extending to pinyon-juniper woodlands. |
Elevation | (200–)400–1700 m. ((700–)1300–5600 ft.) | 1200–2200 m. (3900–7200 ft.) |
Distribution |
AL; AR; CT; DE; FL; GA; IN; KY; MA; MD; ME; MI; MO; NC; NH; NJ; NY; OH; PA; SC; TN; VA; VT; WV; ON |
NM; TX; Mexico (Coahuila) |
Discussion | Oenothera nutans is a PTH species and forms a ring of 14 chromosomes or a ring of 12 and 1 bivalent in meiosis, and is self-compatible and autogamous (W. Dietrich et al. 1997). It has plastome III and a BB genome composition. The disjunct occurrences of O. nutans in Arkansas and Missouri probably represent unintentional introductions by humans. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Oenothera nealleyi is restricted to an area from trans-Pecos Texas and northern Coahuila, Mexico, north to Bernalillo and Torrance counties, New Mexico. P. H. Raven and D. P. Gregory (1972[1973]) considered O. nealleyi to represent an unevenly intergrading entity with O. suffulta based on merging of distinguishing characteristics. The known intermediates occur in Terrell County, Texas, and were previously described as Gaura suffulta var. terrellensis Munz, but until new data on its status are available, we include this name with O. nealleyi. The molecular data (K. N. Krakos, unpubl.) suggest that O. nealleyi is not as closely related to O. suffulta as suggested by Raven and Gregory, given the placement in the phylogeny and the difference in scent profiles for these two taxa. Oenothera suffulta is a member of a strongly supported clade that also includes O. patriciae and O. triangulata, while O. nealleyi is a member of a polytomy that consists of other species of subsect. Gaura, with the O. suffulta—O. triangulata—O. patriciae clade sister to it (W. L. Wagner et al. 2013). Oenothera nealleyi has a strong sweet scent, whereas O. suffulta does not have a discernible scent (Wagner et al.). Raven and Gregory determined O. nealleyi to be self-incompatible. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | O. austromontana, O. biennis subsp. austromontana, O. biennis var. austromontana, O. biennis var. nutans | Gaura nealleyi, G. suffulta subsp. nealleyi, G. suffulta var. terrellensis, O. suffulta subsp. nealleyi |
Name authority | G. F. Atkinson & Bartlett: Rhodora 15: 83. (1913) | (J. M. Coulter) Krakos & W. L. Wagner: PhytoKeys 28: 64. (2013) |
Web links |